STROPHOMEMA OPHIDLVNA. 113 



worthy features. The papillae are fairly numerous, especially ventrally where 

 they project somewhat above the external surface of the body. Their shape 

 and general character are represented in Plate 33, fig. 9. Small yellowish gran- 

 ules are scattered throughout the cuticle, but of their origin or function it is 

 impossible to make anj- definite statements. The spines are shown (Plate 36, 

 fig. 17). 



The sensory atrium is exceptionally small (Plate 8, fig. 5) and the two outer 

 ridges appear to be lacking altogether. The inner ridge, on the other hand, is 

 clearly developed and typically placed but is of limited extent. The cirri in 

 this genus are united as usual in groups of 2-5 and are composed of the customary 

 cubical pigmented cells. Posteriorly the atrium opens into the buccal-pharyn- 

 geal tube, a long slender structure of about the same calibre throughout. Its 

 lining is composed of slender epithelial celfe produced into longitudinal folds 

 especially in the anterior half. External to the epithelium is a well-developed 

 layer of circular muscles and in contact with this a sheet of longitudinal fibres 

 which become more abundant in the neighborhood of the stomach-intestine. 

 In its anterior fourth this section of the digestive tract is attached to a consider- 

 able number of fibres which extend more or less radially to the body wall. Pos- 

 terior to this region gland cells, arranged in small pear-shaped groups, are 

 imbedded in the longitudinal muscle fibres and by intercellular canals open 

 into the gut. The beautifully regular arrangement of these organs is shown 

 (Plate 17, fig. 13). 



Ordinarily the stomach-intestine connects with the posterior end of the 

 pharynx or oesophagus, but in the present species such is not the case, for this 

 junction is considerably in front of the ventral salivary glands which are append- 

 ages of the pharynx. However the ventral wall of the gut from the dorsal 

 intestinal coecum to the openings of the salivary ducts and for an equal distance 

 posteriorly is clearly pharyngeal in character, lacking the hepatic cells but pos- 

 sessing the characteristic muscle layers. 



The ventral salivary glands are relatively long tubular structures penetrated 

 eccentrically by a thin epithelial tube through which the outlying glandular 

 cells open. Close to the outlet into the pharynx this glandular portion disap- 

 pears, and the delicate duct makes its way through the ventral side of the 

 pharynx to open into a small cul de sac. 



No radula is present. 



The extent and relations of the anterior intestinal coecum are well repre- 

 sented (Plate 8, fig. 5) and the intestine conforms so closely to the usual type that 



